An overlooked mandibular-rubbing behavior used during recruitment by the African weaver ant, Oecophylla longinoda.

Roux O, Billen J, Orivel J, Dejean A - PLoS ONE (2010)

Bottom Line:
We demonstrate that this behavior is used to recruit nestmates.Its frequency varies with the rate at which a new territory, a sugary food source, a prey item, or an alien ant are discovered.So, by rubbing their mandibles onto the substrate, the workers probably spread a secretion from these glands that is involved in nestmate recruitment.

ABSTRACTIn Oecophylla, an ant genus comprising two territorially dominant arboreal species, workers are known to (1) use anal spots to mark their territories, (2) drag their gaster along the substrate to deposit short-range recruitment trails, and (3) drag the extruded rectal gland along the substrate to deposit the trails used in long-range recruitment. Here we study an overlooked but important marking behavior in which O. longinoda workers first rub the underside of their mandibles onto the substrate, and then--in a surprising posture--tilt their head and also rub the upper side of their mandibles. We demonstrate that this behavior is used to recruit nestmates. Its frequency varies with the rate at which a new territory, a sugary food source, a prey item, or an alien ant are discovered. Microscopy analyses showed that both the upper side and the underside of the mandibles possess pores linked to secretory glands. So, by rubbing their mandibles onto the substrate, the workers probably spread a secretion from these glands that is involved in nestmate recruitment.

pone-0008957-g001: Illustrations of the posture of marking workers.Includes a case where a worker is marking while nestmates are spread-eagling a Camponotus worker (upper left photo).

Mentions:
Therefore, the landmarks deposited by Oecophylla affect competing ant colonies, facilitate mutualistic and parasitic activities, and deter herbivorous insects. While rearing O. longinoda colonies, we noted each time that we provisioned them that some workers (both majors and minors) often rubbed the Petri dish containing the food first with the underside of their mandibles and then with the upper side in a surprising posture (Fig. 1). Sometimes they only rubbed the underside. We hypothesized that this might correspond to a new kind of marking behavior used to locally inform nestmates of a new event on the territory. We therefore conducted a series of experiments to verify if this behavior is triggered when the ants discover (1) a new territory (the Petri dish), (2) prey (frozen crickets furnished during the experiment), or (3) even alien ants. We then looked for the presence of glands thought to be responsible for the secretion of compounds during this behavior.

pone-0008957-g001: Illustrations of the posture of marking workers.Includes a case where a worker is marking while nestmates are spread-eagling a Camponotus worker (upper left photo).

Mentions:
Therefore, the landmarks deposited by Oecophylla affect competing ant colonies, facilitate mutualistic and parasitic activities, and deter herbivorous insects. While rearing O. longinoda colonies, we noted each time that we provisioned them that some workers (both majors and minors) often rubbed the Petri dish containing the food first with the underside of their mandibles and then with the upper side in a surprising posture (Fig. 1). Sometimes they only rubbed the underside. We hypothesized that this might correspond to a new kind of marking behavior used to locally inform nestmates of a new event on the territory. We therefore conducted a series of experiments to verify if this behavior is triggered when the ants discover (1) a new territory (the Petri dish), (2) prey (frozen crickets furnished during the experiment), or (3) even alien ants. We then looked for the presence of glands thought to be responsible for the secretion of compounds during this behavior.

Bottom Line:
We demonstrate that this behavior is used to recruit nestmates.Its frequency varies with the rate at which a new territory, a sugary food source, a prey item, or an alien ant are discovered.So, by rubbing their mandibles onto the substrate, the workers probably spread a secretion from these glands that is involved in nestmate recruitment.

ABSTRACTIn Oecophylla, an ant genus comprising two territorially dominant arboreal species, workers are known to (1) use anal spots to mark their territories, (2) drag their gaster along the substrate to deposit short-range recruitment trails, and (3) drag the extruded rectal gland along the substrate to deposit the trails used in long-range recruitment. Here we study an overlooked but important marking behavior in which O. longinoda workers first rub the underside of their mandibles onto the substrate, and then--in a surprising posture--tilt their head and also rub the upper side of their mandibles. We demonstrate that this behavior is used to recruit nestmates. Its frequency varies with the rate at which a new territory, a sugary food source, a prey item, or an alien ant are discovered. Microscopy analyses showed that both the upper side and the underside of the mandibles possess pores linked to secretory glands. So, by rubbing their mandibles onto the substrate, the workers probably spread a secretion from these glands that is involved in nestmate recruitment.